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rtc: rv8803: convert spin_lock to mutex_lock 

Fix a scheduling while atomic issue caused by rv8803_set_time()
holding a spinlock during the call to i2c_smbus_read_byte_data().

Signed-off-by: Oleksij Rempel <fixed-term.Oleksij.Rempel@de.bosch.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
This commit is contained in:
Oleksij Rempel 2016-02-04 13:45:20 +01:00 committed by Alexandre Belloni
parent 7444845b08
commit 9d1fa4c373
1 changed files with 18 additions and 21 deletions
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39
drivers/rtc/rtc-rv8803.c
View File

@ -52,7 +52,7 @@
struct rv8803_data {
struct i2c_client *client;
struct rtc_device *rtc;
spinlock_t flags_lock;
struct mutex flags_lock;
u8 ctrl;
};
@ -63,11 +63,11 @@ static irqreturn_t rv8803_handle_irq(int irq, void *dev_id)
unsigned long events = 0;
int flags;
spin_lock(&rv8803->flags_lock);
mutex_lock(&rv8803->flags_lock);
flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
if (flags <= 0) {
spin_unlock(&rv8803->flags_lock);
mutex_unlock(&rv8803->flags_lock);
return IRQ_NONE;
}
@ -102,7 +102,7 @@ static irqreturn_t rv8803_handle_irq(int irq, void *dev_id)
rv8803->ctrl);
}
spin_unlock(&rv8803->flags_lock);
mutex_unlock(&rv8803->flags_lock);
return IRQ_HANDLED;
}
@ -155,7 +155,6 @@ static int rv8803_set_time(struct device *dev, struct rtc_time *tm)
struct rv8803_data *rv8803 = dev_get_drvdata(dev);
u8 date[7];
int flags, ret;
unsigned long irqflags;
if ((tm->tm_year < 100) || (tm->tm_year > 199))
return -EINVAL;
@ -173,18 +172,18 @@ static int rv8803_set_time(struct device *dev, struct rtc_time *tm)
if (ret < 0)
return ret;
spin_lock_irqsave(&rv8803->flags_lock, irqflags);
mutex_lock(&rv8803->flags_lock);
flags = i2c_smbus_read_byte_data(rv8803->client, RV8803_FLAG);
if (flags < 0) {
spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
mutex_unlock(&rv8803->flags_lock);
return flags;
}
ret = i2c_smbus_write_byte_data(rv8803->client, RV8803_FLAG,
flags & ~RV8803_FLAG_V2F);
spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
mutex_unlock(&rv8803->flags_lock);
return ret;
}
@ -226,7 +225,6 @@ static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
u8 alarmvals[3];
u8 ctrl[2];
int ret, err;
unsigned long irqflags;
/* The alarm has no seconds, round up to nearest minute */
if (alrm->time.tm_sec) {
@ -236,11 +234,11 @@ static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
rtc_time64_to_tm(alarm_time, &alrm->time);
}
spin_lock_irqsave(&rv8803->flags_lock, irqflags);
mutex_lock(&rv8803->flags_lock);
ret = i2c_smbus_read_i2c_block_data(client, RV8803_FLAG, 2, ctrl);
if (ret != 2) {
spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
mutex_unlock(&rv8803->flags_lock);
return ret < 0 ? ret : -EIO;
}
@ -253,14 +251,14 @@ static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
err = i2c_smbus_write_byte_data(rv8803->client, RV8803_CTRL,
rv8803->ctrl);
if (err) {
spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
mutex_unlock(&rv8803->flags_lock);
return err;
}
}
ctrl[1] &= ~RV8803_FLAG_AF;
err = i2c_smbus_write_byte_data(rv8803->client, RV8803_FLAG, ctrl[1]);
spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
mutex_unlock(&rv8803->flags_lock);
if (err)
return err;
@ -289,7 +287,6 @@ static int rv8803_alarm_irq_enable(struct device *dev, unsigned int enabled)
struct i2c_client *client = to_i2c_client(dev);
struct rv8803_data *rv8803 = dev_get_drvdata(dev);
int ctrl, flags, err;
unsigned long irqflags;
ctrl = rv8803->ctrl;
@ -305,15 +302,15 @@ static int rv8803_alarm_irq_enable(struct device *dev, unsigned int enabled)
ctrl &= ~RV8803_CTRL_AIE;
}
spin_lock_irqsave(&rv8803->flags_lock, irqflags);
mutex_lock(&rv8803->flags_lock);
flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
if (flags < 0) {
spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
mutex_unlock(&rv8803->flags_lock);
return flags;
}
flags &= ~(RV8803_FLAG_AF | RV8803_FLAG_UF);
err = i2c_smbus_write_byte_data(client, RV8803_FLAG, flags);
spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
mutex_unlock(&rv8803->flags_lock);
if (err)
return err;
@ -333,7 +330,6 @@ static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
struct i2c_client *client = to_i2c_client(dev);
struct rv8803_data *rv8803 = dev_get_drvdata(dev);
int flags, ret = 0;
unsigned long irqflags;
switch (cmd) {
case RTC_VL_READ:
@ -355,16 +351,16 @@ static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
return 0;
case RTC_VL_CLR:
spin_lock_irqsave(&rv8803->flags_lock, irqflags);
mutex_lock(&rv8803->flags_lock);
flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
if (flags < 0) {
spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
mutex_unlock(&rv8803->flags_lock);
return flags;
}
flags &= ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F);
ret = i2c_smbus_write_byte_data(client, RV8803_FLAG, flags);
spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
mutex_unlock(&rv8803->flags_lock);
if (ret < 0)
return ret;
@ -441,6 +437,7 @@ static int rv8803_probe(struct i2c_client *client,
if (!rv8803)
return -ENOMEM;
mutex_init(&rv8803->flags_lock);
rv8803->client = client;
i2c_set_clientdata(client, rv8803);